A well-known coupling toy, known as a chinese finger, employs a net-like woven structure which expands transversely due to compression when coupling engagement is made and contracts transversely when a pull-apart force is applied. It is also well known to connect a flexible tube to a rigid metal tube. Another coupling of interest is the paper file described in U.S. Pat. No. 828,974 to Schmidmer wherein a rigid U-shaped metal insert fits into upwardly extending springs. In U.S. Pat. No. 3,263,444 to DiCroce, a finger ring is described wherein a polyethylene insert-coupling, having a compressible enlarged end, is insertable into a comparably shaped recess of a metal ring.